https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110919
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot
gnu.org
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
After reassoc1 we have:
_19 = _6 == iftmp.1_8;
_3 = iftmp.1_8 ^ 1;
_21 = (_Bool) _3;
_23 = _6 != 0;
_10 = _19 & _23;
_5 = _10 & _21;
Which is: (_6 != 0) & (_6 == iftmp.1_8) But since we know that iftmp.1_8 only
has 2 values, we could optimize this to: (_6 == 1) & (iftmp.1_8 == 1)
Reduced testcase:
```
_Bool f(int a, int b)
{
b &= 1;
_Bool t = a == b;
int c = b^1;
_Bool d = c;
_Bool e = a;
_Bool g = t & d;
_Bool h = g & e;
return h;
}
```
This should return false always.
So something like:
(simplify
(bit_and:c (eq:c @0 @1) (ne:c @0 INTEGER_CST@2))
(if (has_two_value_range (@1))
(with {
tree other_value = ...;
}
(bit_and (eq @0 { other_value; }) (eq @1 { other_value; }))
)
)
)
